American Audio VELOCITY - REV 4-05 Betriebsanleitung PDF herunterladen (Seite 110)

METRO RAIL DESIGN CRITERIA SECTION 9 / SYSTEMS

DE304.09 9-105 Revision 4 : 05/09/12

Metro Baseline Re-Baseline: 04/29/10

B. Design Criteria

1. The PA subsystem shall comply with NFPA 72 and shall be compliant with

listing requirement of the California State Fire Marshall wherever used as

part of a combination fire system.

2. Technical Characteristics

a. Active Components: Solid-state devices.

b. Power Output: As required.

c. Headroom: Sufficient to allow a minimum increase in output of 12 Db,

without increase in hum, noise, or total harmonic distortion.

d. Frequency Response:

1) End-to-end Station amplifier to speaker frequency response: 1.5 Db

from 100 Hz to 10 Khz, 3.0 Db 10 Khz to 15 Khz.

2) Pre-recorded audio messages shall be capable of being recorded,

stored and delivered at CD quality encoding (44 Khz, 16-bit) from

both the ROC server and the local digital message repeater.

3) Live Microphone audio shall be encoded and delivered at a minimum

of 22 Khz, 8-bit.

e. Total Harmonic Distortion: Not greater than 1 percent at full rated

output.

f. Distribution: 70 V nominal, transformer isolated.

g. Power Source: Un-interruptible Power supply.

h. Overload Protection: All amplifier outputs shall be protected with

automatically resetting thermal overload, short circuit and current limited

protection.

i. PA subsystem shall maintain a uniformly distributed sound level at least

10 dB above ambient station operating noise level measured at 5 ft

above floor for indoor stations. Outdoor stations shall be not less than

60 dBA plus or minus 30 degrees off Axis, 4 feet above the floor, at

vehicle ambient noise level.

The minimum sound level at any point 5 ft. or lower, above the floor

sound level shall be:

1) Mezzanine: 70 dBA minimum

2) Platform: 78 dBA minimum

3) Yard and High Bay Areas: 78 dBA minimum

4) Ancillary: 70 dBA minimum

5) Low Bay, ROC, and Offices: 70 dBA minimum.

6) Horn speakers’ frequency response shall be in the range of 150 hz to

15 khz.

1 2 ... 105 106 107 108 109 110 111 112 113 114 115 ... 190 191

Keine Kommentare

American Audio VELOCITY - REV 4-05 Betriebsanleitung Seite 110